The successful local excision of benign liver tumors has fostered a more aggressive surgical approach to the excision of hepatic metastases of colorectal malignancies. During the first 2 or more years after the removal of a colorectal tumor, carcinoembryonic antigen (CEA) levels are measured every 3 months. When the CEA level begins to rise, recurrence must be considered. In the absence of proof of metastasis or recurrence in the rectum, colon, lung, or peritoneal cavity, a search is made for hepatic metastases. Imaging by CT, MRI, or PET scans is performed. Hepatic angiography is usually not necessary and has been replaced by CT or MRI with coronal reconstruction to define regional anatomy. Any evidence of liver metastases requires an evaluation of the number, size, and location of the metastases. It is hoped that none or only one or two solitary metastases will be verified in locations easily accessible to the surgeon. The age and general condition of the patient, as well as the size, number, and locations of metastases, are considered in making a decision to attempt curative resection. Given the sensitivity of modern imaging, “blind” abdominal exploration for rising CEA in the absence of radiographic abnormalities is discouraged. The patient should be fully informed and should participate in making a decision to re-operate. The patient should be made aware that a major portion of the liver may need to be excised. A residual of 20% or more of normal liver tissue remaining in the left lobe is essential for survival but this number may exceed 30% if heavily pretreated with chemotherapy.
Perioperative antibiotics are given, and any blood deficiency is corrected. Studies should have ruled out metastases to the lungs and general peritoneal cavity insofar as possible.
A general anesthetic that has minimal potential to harm the liver is required.
The patient is placed flat on the table with arms extended and accessible to the anesthesiologist.
The skin of the thorax and abdomen is prepared, since the incision may extend from over the lower sternum to below the umbilicus. Bilateral large bore IVs are mandatory in anticipation of substantial blood loss. Central venous catheters should be considered standard for major liver surgery and intraoperative monitoring of central venous pressure is helpful. Resistance to large volume resuscitation so as to maintain a CVP <6 greatly reduces blood loss. Once parenchymal transection is complete and large bleeding points addressed, aggressive fluid resuscitation should be undertaken. Continuous arterial pressure monitoring is mandatory.
A long right subcostal incision that extends across the midline as a bilateral subcostal incision provides excellent exposure. Alternatively, a liberal midline incision extending from well above the xiphoid to or below the umbilicus may be used but makes mobilization of a large liver lobe much more difficult, particularly in a larger patient.